I am going to agree with the water ballast theory, this is how 99% of the evasive species have been transfered around the world, and the reason why there are sevear regulations about how and where you can ballast or deballast your ships now.

Steve

well first of all, where did you get 99% from? US EPA states "Over two-thirds of recent non-native species introductions in marine and coastal areas are likely due to ship-borne vectors, and ballast water transport and discharge is the most universal and ubiquitous of these". I do agree that this is a severe problem and is far from addressed despite ballast fill/discharge regulations.

lions associate with reefs and i have a hard time seeing ports sustaining a good enough environment to sustain a them. so i remain dubious concerning the lions-by-ballast theory. im much more inclined to blame it on ignorance of well meaning people... actions with the best intentions applied carelessly can often lead to the most devastating results. and "i didn't know" isn't a good enough excuse to me.

Just wondering, do ships even fill ballasts near any reefs. I would think the lionfish count in a harbour would be real low. I'd vote Aquarists.

the 99 was a number out of my head, just meant a high amount.

Lion fish are around reefs, yes, but also around man made structures that substitute as artificial reefs, so in theory they could suck up all kinds of fish around old established jetties in the tropics.